• Title/Summary/Keyword: stand-off

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The Improved Characteristics of the Stand-alone PV System by the Independent Battery Control Method (밧데리 개별 제어 방식에 의한 소규모 독립형 태양광 발전 시스템의 특성 개선)

  • 강신영;이양규;김광헌
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.5
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    • pp.482-489
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    • 2002
  • This paper studies the stand-alone photovoltaic system for the solar lighting lamp. The solar lighting lamp has PV modules, batteries, and charge & discharge system. The charge efficiency is improved for the control of each battery which is divided the charge from the discharge to change the structure of existing solar lighting lamp charge & discharge system. so, the charge and discharge times are reduced of 50% and the depth of discharge control can be controlled in the discharge cut off voltage. It can be effective of the battery use. If a battery is out of order, this system can be executed for a regular period. So we saved the repair cost and developed of system's stabilization. It Is possible to make economical effects to apply for solar lighting lamp used photovoltaic system.

The Usability of Sit to Stand Test Performance in Chronic Stroke (만성 뇌졸중 환자들의 Sit to Stand Test의 임상적 유용성)

  • Cho, Hwi-Young;An, Seung-Heon;Lee, Yun-Bok;Hong, Hyun-Hwa;Lee, Gyu-Chang
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.4
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    • pp.549-558
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    • 2013
  • PURPOSE: This study is designed as a retrospective study, and identified the clinical usability of Sit to Stand (STS) test for predicting of fall incidence in stroke patients who experienced a fall within 1 year. METHODS: Between July 2011 and November 2012, 69 inpatients with stroke in K rehabilitation hospital were participated under voluntarily signing the informed consent form. STS test and 10m walk test (10MWT) were used to assess the muscle strength of lower-extremity and walking velocity, respectively. Also, we tested dynamic balance and motor function of lower-extremity in affected-side using with the Berg balance scale (BBS) and the Fugl-Meyer assessment of lower extremity (FM-L/E). METHODS: There were significant differences between subjects with fall-experienced group and without subjects without fall-experienced group in STS test, 10MWT, BBS scores and FM-L/E. STS test significantly showed a negative correlation between 10MWT (r=-.657), BBS (r=-.512), and FM-L/E (r=-.563). And, 10MWT have a influence on the performance of STS test (the capacity of explanation = 20%). The cut-off value of STS performance predicting falls experience is ${\geq}14.36$ seconds (sensitivity=76%; specificity=79%, area under curve=.785). According to logistic regression analysis of falls experience, subjects ${\geq}14.36$ s showed that 4.164 times (odd ratio) increased in falls than subjects < 14.36 s in STS test. CONCLUSION: This study demonstrated that STS test may be a useful tool predicting and measuring falls in patients with stroke. Further study will be needed to elucidate the kinematic analysis of STS test and the relationship between physical activity level and falls in stroke patients.

Study on the Estimation of Volume Increment for the Pitch Pine Forest (임분생장량(林分生長量) 추정(推定)에 관(關)한 연구(硏究))

  • Lee, Yeo Ha
    • Journal of Korean Society of Forest Science
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    • v.18 no.1
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    • pp.9-12
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    • 1973
  • Volume increment and estimation of future growth of pitch pine stand at age of 16 were analyzed based on the stand table method. The diameter growth survey was made by the Meyer's Increment Borer method which was based on the volume formular made on the single tree volume. The formular is V=0.000058D $^{1.6}{\times}H^{1.1}$ This survey was made based on the 95% reliability surveyed on the 339 trees in the 0.33ha of sample plot espicially set up. (1) Linear regression over annual diameter growth for the diameter is as follows; y=0.1618+0.0298x (2) Ninety percent of the total trees, in the diameter distribution of 2cm round off, each increased one step in diameter. (3) Stand volume increment percentage shows 16%. (4) The increment of stand volume for 5 years shows 46% of increment rate.

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Motion Characteristics of Particle in Model GIS (모의 GIS내 금속이물의 거동특성)

  • 김경화;이재걸;곽희로
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.4
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    • pp.152-159
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    • 1999
  • This paper describes the rmtion characteristics of a particle in GIS under AC voltage. To measure the motion characteristics of the particle, a model gas chamber and parallel plain electrodes were designed and manufactured lift-off voltages of wire and spherical particles on the electrode were calculated and rreasured, and electric charge was calculated. By using a high speed carrera, the rmtion characteristics of various particles with aw}ied voltages, such as motion pattern, lift-off time, lift-off height, were analyzed 1be lift-off voltages were greatly affected by diarreters of wire and spherical particles. At voltage around lift-off voltage, the stand-up particle in vertical state rmved up and down between electrodes and the height of the lift-off particle was low. At voltage around breakdown voltage, the particle repeated vertical rotation a few times while they were being lifted off, and then, they were floating between the electrodes.trodes.

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Micromachining of Pyrex Class for Accelerometer (가속도 센서용 파이렉스 유리의 미세가공)

  • 김광현;최영현;최종순;박동삼;유우식
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.268-273
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    • 2002
  • The mechanical etching technique has recently been developed to a powder blasting technique for various materials, capable of producing micro structures larger than 100$\mu\textrm{m}$. This paper describes the performance of powder blasting technique in micromachining of pyrex for the accelerometer sensor and the effect of the number of nozzle scanning and the stand-off distance on the erosion depth.

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Power Control of Small Wind Power System (소형 풍력발전시스템의 출력제어)

  • Kim, Chul-Ho;Lee, Hyun-Chae;Seo, Young-Taek;Cho, Hwan-Kee
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1066_1067
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    • 2009
  • Wind power is one of most promising renewable energy. The output capacity of large wind turbine has been increased for off-shore application. Number of installation of small wind turbine also has been increased for the stand-alone and off-grid application of remote area and recently small wind turbine equipped with lamp on the pole is used for street lamp. Maximum wind energy must be extracted by wind turbine within rated wind speed. Power must be controlled to protect the system such as blade, generator, and power system above the rated wind speed. In this paper, small wind power system of 800W rating for battery charging is implemented and output power control by furling system is verified at wind tunnel test.

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A Development of Data-Driven Aircraft Taxi Time Prediction Algorithm (데이터 기반 항공기 지상 이동 시간 예측 알고리즘 개발)

  • Kim, Soyeun;Jeon, Daekeun;Eun, Yeonju
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.2
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    • pp.39-46
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    • 2018
  • Departure Manager (DMAN) is a tool to optimize the departure sequence and to suggest appropriate take-off time and off-block time of each departure aircraft to the air traffic controllers. To that end, Variable Taxi Time (VTT), which is time duration of the aircraft from the stand to the runway, should be estimated. In this paper, a study for development of VTT prediction algorithm based on machine learning techniques is presented. The factors affecting aircraft taxi speeds were identified through the analysis of historical traffic data on the airport surface. The prediction model suggested in this study consists of several sub-models that reflect different types of surface maneuvers based on the analysis result. The prediction performance of the proposed method was evaluated using the actual operational data.

The Circuit of Blocking Stand-by Power from Electronic Product using Remote-controller (리모컨을 사용하는 가전제품에서의 대기전력 차단회로)

  • 배영철;김주완
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.05a
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    • pp.452-455
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    • 2001
  • Modem consumer electronic products like TV, VCR etc, offer users the convience of switching the equipment on and off via a remote control handset. When this type of equipments is switched off, it is said to be in standby mode. In this paper, We proposed that the method of the blocking standby power from in industrial product including electronic and electronic appliauces. This method is perfectly blocking the standby power of electrical circuit.

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Impacts of Different Pentachloronitrobenzene (quintozene) Use Patterns on Severity of Damping-off of Ginseng (Panu quinquefolitrs)

  • Reeleder, R.D;Capell, B
    • Journal of Ginseng Research
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    • v.26 no.1
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    • pp.10-16
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    • 2002
  • In replicated field trials, the efficacy of pentachloronitrobenzene (PCNB; quintozene) for control of damping-off of ginseng seedlings was found to be affected by timing of application and formulation. Application at the time of seeding and prior to placement of straw mulch was found to provide the moat consistent level of disease control. However, decline in plant stand during the four-year production cycle resulted in most treatments providing similar levels of plant populations at harvest. Soil residues of pentachloronitrobenzene were generally highest (1 $\mu\textrm{g}$ PCNB/g soil) in those treatments that exhibited the highest levels of disease control in the seedling year. Straw contained high levels of quintozene after application. Beet seed assays with artificially-infested soils indicated that current use rates provide an amount of product suitable for high levels of disease control.

Numerical Simulation on the Steel Plate Cutting Performances of Bent-Shaped Charge Holder Blasting (드로잉 가공 성형폭약용기의 강판절단성능에 관한 수치해석적 연구)

  • Min, Gyeong-Jo;Park, Hoon;Oh, Se-Wook;Park, Se-Woong;Suk, Chul-Gi;Cho, Sang-Ho
    • Explosives and Blasting
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    • v.36 no.3
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    • pp.19-28
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    • 2018
  • Locally damaged structures caused by earthquake or extraordinary external forces have been required to rapidly be dismantled because of its possibility of additional collapses. Particularly, steel frame structures were demolished by the shaped charge blasting method. Recently a research suggested a shape charge blasting technique which uses bent-shaped charge holder of copper plate and emulsion explosive charge to cut thick steel plates. This study simulated the cutting performance of the bent-shaped charge holder with considering types of explosives, thickness of copper liner and stand-off distances using LS-DYNA software. The shape charge blasting test of a 25mm thickness steel plate were used to calibrate the input parameters of the numerical models. The penetration depth and penetration width were analysed with different types of explosives, thickness of copper liner and stand-off distances.